001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.server.core.api.event;
021
022
023import org.apache.directory.api.ldap.model.entry.Entry;
024import org.apache.directory.api.ldap.model.exception.LdapException;
025import org.apache.directory.api.ldap.model.filter.ExprNode;
026import org.apache.directory.api.ldap.model.name.Dn;
027
028
029/**
030 * Tests if an entry is eligible for return by evaluating a filter expression on
031 * the candidate.  The evaluation can proceed by applying the filter on the 
032 * attributes of the entry itself or indices can be used for rapid evaluation.
033 * 
034 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035 */
036public interface Evaluator
037{
038    /**
039     * Evaluates a candidate to determine if a filter expression selects it.
040     * 
041     * @param refinement the filter expression to evaluate on the candidate
042     * @param dn the normalized distinguished name of the entry being tested
043     * @param entry the entry to evaluate
044     * @return <tt>true</tt> if the filter selects the candidate false otherwise
045     * @throws LdapException if there is a database fault during evaluation
046     */
047    boolean evaluate( ExprNode refinement, Dn dn, Entry entry ) throws LdapException;
048}